It is often necessary to calculate the axle load of a motor vehicle to control the operation of the vehicle and/or regulate the vehicle's chassis under varying loads. Known measuring devices for calculating axle loads typically base the calculation on the deflection path of the axle spring assembly in relation to the vehicle's chassis. The measuring devices in turn generate output signals indicative of the deflection.
One problem with such known measuring devices, is that the output signals frequently provide inaccurate deflection measurements. The spring assembly mounted between the axle and the chassis often settles and, as a result, a shift in the zero deflection position occurs. The axle load calculation can therefore correspondingly drift over time.
One approach to this problem is to calibrate the measuring device at regular intervals to achieve long-term stabilization. However, accurate calibration requires special workshop facilities and trained personnel, and is therefore a relatively expensive procedure.
It is an object of the present invention, therefore, to overcome the problems of known methods and apparatus for calculating the axle loads of motor vehicles.